During the past year, our Laboratory has continued its extensive investigation into the pathogenesis of the cutaneous lupus lesions. We have demonstrated that the cutaneous lupus lesion contains predominantly T cells as determined by an immuno-peroxidase technique employing monoclonal antibodies against T helper and suppressor cells. Despite our inability to detect, employing a fluorescein conjugated anti light chain antisera and the presence of significant B cells, a new monoclonal antibody (Leu-10) has detected the presence of some B cells in these lupus lesions. Our studies, however, have failed to demonstrate using an OKMl antisera, the presence of a significant number of macrophages in these lesions. An anti IA antisera, however, demonstrates that the majority of these cells are in their activated form. We conclude from these studies that the predominant cell in the lupus lesion is a T cell (both OKT4 and OKT8, helper and suppressor). Moreover, these T cells are in an activated state. These data have just recently been submitted for publication. We are now designing studies employing a blister machine that will allow us now to isolate the individual cells from a lupus lesion. This blistering machine employs suction and heat (41 C) and creates a small blister measuring approximately 2 mm in diameter at the dermal/epidermal junction. The mononuclear cells will then be harvested from these lupus lesions and rosetted with ox red blood cells on which various fractions of DNA (i.e. UVDNA, single stranded DNA, and native DNA have been absorbed). This experimentation is designed to determine the functional capabilities of the mononuclear cells (predominantly T cells) in the lupus lesions. If we are able to demonstrate binding of these T cells, in the form of rosettes with the DNA coated red blood cells, we will have good presumptive evidence that these lymphocytes are capable of mounting a cell mediated response against nuclear antigens. Similar experiments are to be employed to investigate whether or not these mononuclear cells will react against various fractions of RNA.